Air preheater



June 28, 1938. c. J. HERBECK AIR PREHEATER 2 Sheets-Sheet 1 Filed Aug. 31, 1937 m. fi R f Y 0% w E T N mK .A, 40 0% June 28, 1938. c. J. HERBECK 2,122,176

AIR PREHEATER Filed Aug. 51, 1957 2 Sheets-Sheet 2 ATTO R N EY Patented June 28 1938 PATENT OFFIQE Am PREHEATER.

Charles J. Herbeck, Cedar Rapids, Iowa, assignor to The Air Preheater Corporation, New York,

Application August 31,

5 Claims.

The invention relates to heat transfer devices of the type disclosed in a number of United States patents, e. g. 1,652,025 granted on December 6, 1927, to Frederik Ljungstrom.

In apparatus of this type there is employed a generally cylindrical rotor subdivided into open-ended cells which are filled with a so-called regenerative mass. The rotor is mounted so it lies partly in one of two parallel neighboring passages and partly in theother, the axis of the rotor being in the partition between the two passages, and means being provided to rotate the rotor about its axis. The cells with their regenerative mass always form a part of the passage in which they lie, and the gases flowing through such passage pass through the regenerative mass. Through one of the passages hot gases flow which give up heat to the regenerative mass, and through the other there flow gases to be heated to which the regenerative mass gives up heat. Quite frequently one or another of the two gases contains dust which will collect in the regenerative mass. This is the situation for example where the heating gas is the waste gas from a boiler and the heat absorbing gas is air which may be on its way to the furnace. The gas from the furnace is more or less laden with ash and this at times clogs the rather small openings presented by the mass in the cells.

The object of the present invention is to provide means for cleaning the regenerative mass of such dust.

One illustrative form of the invention will now be described, reference being made to the accompanying drawings. The drawings contain five figures, of which the first is a top view partly in section of a heat transferring device of this sort with my invention applied; Fig. 2 is an enlarged view of a portion of Fig. 1; Fig. 3 is a section on line 3'3 of Fig. 2; and Figs. 4 and 5 are still further enlarged sectional views on lines 44 and 5-5 respectively of Fig. 3. i

It will be assumed in the following description that the reader is familiar with the general structure of devices of this sort and no more details of the general structure will be given than are necessary for an understanding of the present improvement.

The cellular structure or rotor is generally cylindrical and rotates about the axis I. It comprises a cylindrical shell 3 the space within which is subdivided into a number of sectors 55 by the radial partitions. 1-1. Usually the sectors are subdivided into cells by tangential partitions 9-9, this term "tangential partition being used herein to designate partitions which are each tangential to an imaginary cylinder whose axis is at I. Each sector is in the particular form shown thus subdivided into three cells. In these cells is placed the regenerative material which 1937, Serial No. 161,719

alternately absorbs and rejects heat. This material is composed of plates ll which are appropriately corrugated or otherwise shaped. These plates l l are likewise arranged tangentially to imaginary cylinders whose axes are located at l. I

In the particular form used for illustrative purposes herein the regenerative mass is divided into two portions or sections arranged one above the other, as shown clearly in Fig. 3. The upper section A is separated from the lower section B by a space E3. The plates of the upper section A rest on bars l5-l5 and the plates of the lower section B similarly rest on bars l'il1. These bars are secured, as by welding, to the circumferential shell 3 and the partitions 9. The purpose of subdividing the regenerative mass in this manner into upper and lower sections is connected with the question of prolonging the life of the plates and of making the replacement of the material easier, such subdivision being found desirable in cases where the heating gases are of relatively high temperature. I have selected a preheater subdivided in this manner to make it clear that my invention is applicable to such a form as well as to a form of preheater in which the mass is not so subdivided.

As the rotor rotates about the axis 1, the cells containing the plates ii are alternately brought into a channel through which the hot gases flow and into a channel through which the gases to be heated flow. One of these channels may for example lie to the left of the radial partitions lfi-|6 and the other to the right of the radial partitions l8--l,8' as viewed in Fig. 1. The gases will ordinarily flow in opposite directions, 1. e. if the heating gas flows upward through the channels between the plates H, the gases to be heated will flow downward through these channels when the corresponding cell comes to be rotated into the channel for these gases.

My invention has for its purpose the removal of solids that may lodge in the channels between the plates H, and to this end I provide the following means:

Radially placed bars: l9 are arranged'above the sectors, one such bar lying above each sector of the upper section A and likewise one such bar lying above each sector of the lower section B. In the wider portion of the sectors, i. e. the one farthest from the axis 1, each bar is preferably provided with additional or auxiliary bars Illa-i911 secured by appropriate frame work to the bar 59. The bar l9 extends slidably through slots in the partitions 9-41 and is free to move slightly in a radial direction. Secured to the bar l9 and auxiliary bars l9a-l9a and extending downward are arms or plates 2I-2l. These extend for a short distance into spaces between the mass of plates H. The plates l l are packed into their cells loosely enough so that a slight rocking motion in a radial direction is possible, the plates rocking about the points at which they rest on the bars I5 and H. Thus if the bars H! are given a radial motion or jar this will result in a corresponding jarring motion of the plates H which will loosen and dislodge particles that have gathered on the plates. This jarring motion of the rods I9 is produced by the following mechanism.

In each sector a plate 29 is secured to the inner face of shell 3 in any desired way, as by bolts 3|, each plate having integral with it two parallel inwardly extending fins 2l21, between which are pivotally mounted on pins 23 and 24 two levers 25 and 26. Of these the lower one, 25, is connected by pin 28 to the bar I 9 lying above section B, and the upper one, 26, is connected by pin 30 to the bar I!) lying above upper section A. The upper end of lever 25 has secured to it as by welding a pin 33, extending outwardly and carrying at its outer end a head 35. The lower end of lever 26 is bifurcated as at 42 and straddles the upper end of lever 25. The pin 33 is larger in diameter than the lever 25 and the projecting segmental portions engage the branches 4242 of lever 26. The upper end of lever 26 is pivotally connected to bar l9 located above section A. Hammer 31 is mounted pivotally at 39 and is urged resiliently in a direction radial to the rotor by a spring 4|, this spring being mounted at 43, its pressure being regulable by means of the screw 45. This adjusting screw is mounted in the wall of a subsidiary housing 51 which encloses the hammer mechanism sealing the space in which this mechanism is located from the atmosphere and enclosing it with the interior of the heater. The hammer 3! has on it a cam 41 which causes the hammer to be moved outward by the head 35 as the rotor rotates in a clockwise direction as viewed in the drawings. When the head 35 reaches the end of cam 4'? the spring 4| causes the hammer to deliver a sharp blow to head 35 which is transmitted to bars [9 and fingers 2| through the levers 25 and 26.

It will be clear that when there is only one section of the regenerative material there will be only one lever transmitting motion from the hammer to the bars l9.

It will be noted that the jarring blow is by the mechanism described delivered in such a direction that the plates II are jarred away from the axis l. The elasticity of the plates causes them to return to the position they occupied before the blow. If the blow were delivered in the opposite direction, this might cause the plates to wedge between the radial partitions as they would in that case be forced toward a narrower space.

The dust that is jarred loose by the action described above will under the influence of gravity tend to move downward and in general it will be advantageous to have this jarring action occur on that side of the mechanism in which the gases are moving in the same direction. However, at times it may be satisfactory to deliver the blow on the side where the gases are moving upward and to depend on the force of the current to move the particles upward with the gas.

Whereas I have illustrated a single hammer for the preheater, it will be obvious that there might be one or more further hammers distributed along the circumference of the heater.

What I claim is:

1. In a regenerative heat transfer device of the type described comprising a generally cylindrical rotor in which are mounted tangentially arranged plates alternately traversed during the rotation of the rotor by a heat-delivering and a heat-absorbing current of gases, means to clean the plates comprising a bar mounted adjacent to and above the plates radially of the rotor with freedom for some motion in a direction parallel to its own length, arms rigidly secured to the bar at spaced points along its length, and extending into spaces between the plates, and means to jar the bar periodically and thereby to jar the plates and shake adhering solid particles from them.

2. In a regenerative heat transfer device of the type described comprising a generally cylindrical rotor arranged to rotate about its vertically placed axis and divided by radial partitions into a plurality of sectors, the combination of a plurality of plates in each sector packed loosely in tangential position, a member above each sector mounted to have some freedom of motion radially of the rotor, arms rigidly secured to the members and extending into spaces between the plates,

and means actuated by the rotation of the rotor to apply jarring impacts periodically to the members in a direction away from the axis of the rotor, whereby the arms jar the plates and shake oiT particles adhering to them.

3. Apparatus in accordance with claim 2, the

means to apply jarring impacts comprising a lever for each sector one end of which engages the member, and a hammer which delivers blows to the free ends of the levers.

4. Apparatus in accordance with claim 2, the means to apply jarring impacts comprising a lever for each sector one end of which engages the member, a hammer which delivers blows to the free ends of the levers, means resiliently urging the hammer toward the axis of the rotor, and cam means operative with rotation of the rotor first to move the hammer away from the axis and then to release it thereby permitting the resilient means to cause the hammer to deliver its blow.

5. In a regenerative heat transfer device of the type described comprising a generally cylindrical rotor arranged to rotate about its vertically placed axis andmade up of an upper and a lower section each divided by radial partitions into a plurality of sectors, the combination of a plurality of plates in each sector packed loosely in tangential position, a member above each sector of each section mounted to have some freedom of motion radially of the rotor, arms rigidly secured to the members and extending into spaces between the plates, and means to apply jarring impacts to the members comprising two levers for each sector mounted so each engages with one end one of the members of such section, a hammer mounted to deliver blows to the other end of the levers, means resiliently urging the hammer toward the axis of the rotor, and cam means operative with rotation of the rotor first to move the hammer away from the axis and then to release it thereby permitting the resilient means to cause the hammer to'deliver its blow.

CHARLES J. HERBECK. 

